Stevenson, H. H., & Roberts, M. J. (1993). New business ventures and the entrepreneur (4th.ed.). McGraw-Hill.

Stevenson, Howard H., and Michael J. Roberts. New Business Ventures and the Entrepreneur. 4th.ed. Boston: McGraw-Hill, 1993.

Stevenson, Howard H., and Michael J. Roberts. New Business Ventures and the Entrepreneur. 4th.ed. McGraw-Hill, 1993.